Scientists have apparently cracked a 20-year-old mystery surrounding the complex relationship between the AIDS virus and the immune system.
In a paper in the online edition of the British journal Nature, the researchers have explained how certain blood cells are able to fend off the AIDS virus naturally but then drop their defensive shields at a crucial moment -- letting the virus in.
The findings by University of California-San Francisco researchers at the Gladstone Institute of Virology and Immunology open up possibilities for drug development.
Since the earliest days of the AIDS epidemic, scientists have known that infection-fighting white blood cells known as T-cells play a central role in the course of the disease.
HIV, the virus that causes AIDS, seems to feast on these foot soldiers of the immune system, and when the number of T-cells circulating in the blood falls below a certain threshold (a T-cell count of 200 or less), the body is prone to lethal infections.
For more than two decades, AIDS researchers have been puzzled by a paradox: The AIDS virus is devastating to T-cells, but most of the time it cannot infect them. Roughly 95 percent of T-cells that circulate in the blood are in what is called a "resting state." As long as these immune cells are quiet, the AIDS virus leaves them alone.
http://www.detnews.com/2005/health/0504/23/A05-151087.htm
In a paper in the online edition of the British journal Nature, the researchers have explained how certain blood cells are able to fend off the AIDS virus naturally but then drop their defensive shields at a crucial moment -- letting the virus in.
The findings by University of California-San Francisco researchers at the Gladstone Institute of Virology and Immunology open up possibilities for drug development.
Since the earliest days of the AIDS epidemic, scientists have known that infection-fighting white blood cells known as T-cells play a central role in the course of the disease.
HIV, the virus that causes AIDS, seems to feast on these foot soldiers of the immune system, and when the number of T-cells circulating in the blood falls below a certain threshold (a T-cell count of 200 or less), the body is prone to lethal infections.
For more than two decades, AIDS researchers have been puzzled by a paradox: The AIDS virus is devastating to T-cells, but most of the time it cannot infect them. Roughly 95 percent of T-cells that circulate in the blood are in what is called a "resting state." As long as these immune cells are quiet, the AIDS virus leaves them alone.
http://www.detnews.com/2005/health/0504/23/A05-151087.htm